Influences of ion bombardment, grain size, and gamma irradiation on surface topography, microstructural, and mechanical characteristics of Cu-2 wt% Sb alloy

Abstract

Abstract The Cu-2 wt% Sb alloy was prepared and exposed to various heat treatments at temperatures ranging from 573 to 973 K to get distinct grain diameters. Different samples of various grain diameters were individually sputtered in an argon glow discharge for various times (0.5, 1, 2 h) using a DC magnetron sputtering device. The surface topography and microstructural features of a Cu-2 wt% Sb alloy were examined utilizing an optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The $$Cu_{3} Sb$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>C</mml:mi> <mml:msub> <mml:mi>u</mml:mi> <mml:mn>3</mml:mn> </mml:msub> <mml:mi>S</mml:mi> <mml:mi>b</mml:mi> </mml:mrow> </mml:math> IMC phase was found to segregate at the grain boundaries. Results showed that the topographical features of sputtered samples (grain boundaries, tiny cones, cratered cones, and etch pits) were mainly affected by grain size and sputtering time. Moreover, the mechanical properties of a Cu-2 wt% Sb alloy were examined. The parameters of the stress–strain curves (Young modulus Y, 0.2% offset stress σ y0.2 , fracture stress σ f , parabolic work-hardening coefficient $${\upchi }_{{\text{p}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>χ</mml:mi> <mml:mtext>p</mml:mtext> </mml:msub> </mml:math> , and ductility $${\upvarepsilon }_{{\text{f}}} {\text{\% }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>ε</mml:mi> <mml:mtext>f</mml:mtext> </mml:msub> <mml:mrow> <mml:mtext>\%</mml:mtext> <mml:mspace/> </mml:mrow> </mml:mrow> </mml:math> ) were measured under different testing conditions. Generally, these stress parameters decrease as the grain diameter increases. These parameters, with the exception of $${\upvarepsilon }_{{\text{f}}} {\text{\% }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>ε</mml:mi> <mml:mtext>f</mml:mtext> </mml:msub> <mml:mrow> <mml:mtext>\%</mml:mtext> <mml:mspace/> </mml:mrow> </mml:mrow> </mml:math> , increase as the strain rate increases, while $${\upvarepsilon }_{{\text{f}}} {\text{ \% }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>ε</mml:mi> <mml:mtext>f</mml:mtext> </mml:msub> <mml:mrow> <mml:mspace/> <mml:mtext>\%</mml:mtext> <mml:mspace/> </mml:mrow> </mml:mrow> </mml:math> decreases as the strain rate increases. Additionally, selective samples of the present alloy were irradiated using γ-radiation with different doses 0.5, 1, 1.5, and 2 MGy. The Vickers microhardness of annealed and irradiated samples lowered as the grain size augmented, while it increased as the irradiation dose increased. Based on the obtained activation energy Q value of 20.65 kJ/mol., it is indicated that the predominant deformation mechanism in the Cu-2 wt% Sb alloy is the motion of dislocation through the Cu-matrix.